(A) Field of the Invention
The present invention relates to a method of performing automatic figure segmentations on pictures of animals or other life forms, and more particularly, relates to a method of performing automatic segmentations applicable to said pictures by segmenting the image into a corresponding tri-map of foreground, background, and unknown regions.
(B) Description of the Related Art
Image segmentation and matting are hot topics in the areas of computer vision and pattern recognition, due to their potential applications in background substitution, general object recognition, and content-based retrieval. Static images, unlike the objects in video, lack temporal correlation between consecutive frames and thus make the problems severely under-constrained. Therefore, user interaction, such as scribble interface, is usually required to produce a complete labeling of the pixels.
Single-image matting approach is one of the typical approaches for static image segmentation. This approach assumes that intensity of each (xi,yi)-th pixel in an input image is a linear combination of a foreground color F and a background color Bi, and intensity may be calculated as:Ii=αiFi+(1−αi)Bi,
where αi is referred to as the pixel's partial opacity value or alpha matte. For each pixel in a color image, there are 3 compositing equations in 7 unknowns. The natural image matting, however, poses no restrictions on the background and is inherently under-constrained. In order to resolve the problem, the user is required to provide some additional information in the form of a tri-map or a set of brush strokes (scribbles). Accordingly, automatic segmentation is not attainable for such method.